<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>JavaScript</title>
</head>
<body>
<input type="button" value="飘飘" onclick="alert('飘飘是个大傻呗')">
<script>

    var arr2 = [1, 2, 'haha', false];
    console.log(arr2)
    arr2.splice(3,1)
    function sayHello(a,b){
      return a+b;
    }
    var sum=sayHello(1,2);
    console.log(sum);
</script>
</body>
</html>